SPC570Sxx Bootloader: Check valid application

[LeoC]

Hi,

My setup:

• SP570S-DISP Demo Board Evaluation
• uC: SPC570S50E1
• IDE: SPC5Studio 5.8.1

I'm using example "SPC570Sxx_RLA Bootloader Application for Discovery".

Function "updater_jump()" In "firmware_updater.c" file, jump to application image without checking if there is valid application image.

So, if there isn't a valid application image, bootloader stucks and the only way to restore bootloader functionality is to perform a "physical" reset using button RESET of SPC570S-DISP board.

void updater_jump(void) {
  void (*fptr)(void);
  uint32_t jump_address_pointer;
  vuint32_t jump_address;
 
  jump_address_pointer = updater_config.codeimage1.address + 4UL;
  jump_address = *((vuint32_t*)(jump_address_pointer));
  /*
   * stop peripherals
   */
#if (SPC5_UPDATER_CONN == SPC5_UPDATER_CONN_CAN)
  can_lld_stop (updater_config.can_driver);
 
#else
  sd_lld_stop(updater_config.serial_driver);
#endif
#if (SPC5_UPDATER_ACT == SPC5_UPDATER_ACT_TIMER)
  stm_lld_stop(updater_config.stm_driver);
#endif
 
  updater_lld_stop();
 /*lint -e9074 */
  fptr = (void (*)(void))jump_address;
  fptr();
  /*lint +e9074 */
 
}

I have tried to inspect, using debugger, what happens when microcontroller jump in an address that contain no valid instructions.

I noticed that no exceptions are triggered, microcontroller remains blocked in a memory location with "unknown instruction".

I have tried to enable all IVOR interrupts, but no IVOR condition is triggered.

I would expect to see "IVO6 - Program Interrupt" because there is an "illegal instruction".

My questions:

• Why no IVOR condition is triggered when microcontroller jump in an "unknown instruction"?
• Please, could you suggest me any approach to check if there is a valid application in "which" jump before perform application image jump?

Thanks,

Regards

[zambrano.luigi · Accepted solution]

Hi,

if the new application is designed with SPC5Studio and is compiled to be executed starting from 0x1000000 (as in the example SPC570Sxx_RLA Bootloader Application for Discovery), the first word at address 0x1000000 will be to 0x005A0000 (first word in boot.S) if a valid application is already present to 0x1000000. So, it is possible to check if a valid application is present verifying if the value to the address updater_config.codeimage1.address is to 0x005A0000.

Please, feel free to contact me for any other clarification.

Regards,

Luigi

[LeoC]

Dear Luigi,

It works!

Many thanks for support!

Leonardo